1. Field of the Invention
The invention relates generally to video decoders, and more particularly to methods and apparatus to speed up operations of Huffman decoders.
2. Description of the Related Art
Huffman codes are very widely used in the area of data compression. Canonical Huffman codes are of special interest as they improve the efficiency of the decoding process, make decoding easier, and have become one of the entropy coding strategies that are commonly used in multimedia applications, such as Real Video standard. However, existing Huffman decoders require substantial use of specialized independent hardware components, such as adders, subtractors and comparators, etc., to accomplish the decompression of canonical Huffman encoded data, which increases production cost and induces critical path delays, thus decreasing the decoding speed. Hence, existing Huffman decoders may encounter problems in some applications; for example, in a full high definition (full HD) resolution implementation (1920 by 1080 pixels per frame) since with the critical path delays, the decoders are unable to accommodate speed requirements of real-time processing. Thus, a need exists for an improved method and apparatus to achieve real time throughput for decoding of a HD resolution video bit stream employing canonical Huffman coding technique, such as Real Video bit stream.